PORT ANGELES — A study in the works since 2008 that will allow the cleanup of the former mill site owned by Rayonier Inc. to move forward has been finalized by the state Department of Ecology.

Ecology officials released the final version of the Port Angeles Harbor sediment study and a supplement to it Thursday after receiving public comment and making changes in response to the input, said Diana Smith, Ecology’s public involvement coordinator.

The finalized study findings will allow Rayonier to work on studies necessary for the cleanup of contaminants from the former mill site near the city’s wastewater treatment plant, Smith explained.

The 75-acre area on the waterfront has been an Ecology cleanup site since 2000. Pockets of contamination — PCBs, dioxins and other toxic chemicals — were left by the mill when it closed in 1997 after 68 years of operation.

Warren Snyder, the site cleanup project manager for Rayonier, said the finalized data will allow Rayonier to move on to the next step in the cleanup process.

“[The finalized reports] were the next milestone of activity,” Snyder said.

The study, released for public comment earlier this year, found the Rayonier site and the bottom of the western part of Port Angeles Harbor to be contaminated with a number of pollutants, such as arsenic and mercury, associated with industrial activities.

The finalized study and its supplement will create better understanding of contaminants in the harbor, said Connie Groven, project manager for the west harbor cleanup.

Preparation for the harbor cleanup has begun. The city and other parties already are working toward an agreed order that will allow the harbor cleanup to progress.

“They’ve already accepted [the data in the report], and they’re moving forward,” Groven said in a Thursday interview.

The documents are available in hard copy at the Port Angeles Public Library, 2210 S. Peabody St.; the Peninsula College library, 1502 E. Lauridsen Blvd.; and the Ecology Southwest Regional Office, 300 Desmond Drive S.E. in Lacey.

The study and supplement received comments from 18 people.

Smith said one of the most commonly commented-on portions of the study was the chemical fingerprinting section, which sought to differentiate potential sources of specific contaminants.

Ecology recognized that there were several recording errors between the tables and the text of the report concerning the fingerprinting analyses and that the results of the analyses were inconclusive, according to a summary of public comments and Ecology responses provided with the finalized report.

For these reasons, Ecology deleted the fingerprinting analyses from the study in preparation for a more extensive fingerprinting analysis, set to be released this spring, Groven said.

Smith said other changes to the final version of the study included updated sediment flow maps for the harbor and more information on the paper pulping processes historically used around the harbor.

Cleanup of the western portion of Port Angeles Harbor is up to the city and five other potentially liable parties, as determined by Ecology.

The city has chiseled out an agreement with three of the other potentially liable parties — the Port of Port Angeles, Nippon Paper Industries USA and Georgia Pacific LLC — to pay a $1 million share of a harbor cleanup project that could take five years total, according to Ecology officials.

The other two are forestry company Merrill & Ring and the state Department of Natural Resources.

The city, the port, Nippon and Georgia Pacific are developing an agreed order with Ecology to investigate the extent of the contamination and evaluate cleanup options, Smith said.

A draft version of the agreed order eventually will be made available for public comment, she added.

“We hope to hold a comment period spring 2013, but it depends on negotiations on the agreed order,” Smith said.

Port Angeles City Manager Dan McKeen included the harbor cleanup project in a list of environmental projects involving Ecology sent to the state agency in October.

The list, sent as a letter requesting grant help from Ecology on the harbor cleanup project, outlines the estimated costs of each project, the total for which could reach $65 million over the next 20 years.

The newly finalized harbor reports also will allow Rayonier officials to work on the marine data summary report, which will detail types of contaminates present in the underwater sediment just north of the upland portions of the site, Smith said.

Smith said the marine report is due to Ecology by March 2013.

Rayonier is completely responsible for cleaning up the former mill site and the marine area to the north.